In general, to guarantee information security, an authentication technique using secret information and a cipher which are common to each other as means for demonstrating self validation is adopted.
For example, an IC card (Smart Card) used in electronic payment includes an IC chip, which holds an ID (identifier) required to identify the IC card and secret information. Furthermore, the IC card has an encryption processing function of executing authentication based on the ID and secret information.
In another example, known is a content copyright protection technique using CPRM (Content Protection for Recordable Media) to demonstrate the validation of an SD card (trademark).